Answer: ?
Step-by-step explanation:
<u>Answers</u>
19 fiction books
7 nonfiction books
<u>Explanation</u>
x + y = 26 ............................................. (i)
x – y = 12 ............................................ (ii)
Elliot added the two equations and the result was
2x = 38.
Dividing both sides by 2;
x = 19
There are 19 fiction books.
Substituting x in equation (i),
x + y = 26 when x = 19
19 + y = 26
y = 26 - 19
= 7
There are 7 nonfiction books
Number of ways to select 3 books from 13 books for adoption is 286 .
<u>Step-by-step explanation:</u>
A Permutation is an ordered Combination. When the order does matter it is a Permutation. There are basically two types of permutation:
- Repetition is Allowed: such as the lock above. It could be "333".
- No Repetition: for example the first three people in a running race. You can't be first and second.
Formula is given by:
, where n is the number of things to choose from, and we choose r of them, no repetitions, order matters. Here , n=13 , r=3.
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
∴ Number of ways to select 3 books from 13 books for adoption is 286 .
Answer:
DE = 24
Step-by-step explanation:
The midsegment DE is half the length of the third side AC , that is
DE =
AC =
× 48 = 24
Y=3.6x is direct variation. The constant is 3.6
8y=2x is the same as y=0.25x. It is direct variation, and the constant is 0.25
1. Assuming "dinners made" is on the y-axis, DV is y=2x. The constant is 2
2. This is not direct variation, and therefore does not have a constant of variation